Method of transferring fluids



July 31, 1951 E. L. HINKSON METHOD OF TRANSFERRING FLUIDS Filed June 26, 1946 5 ma 5 i Ni 70 [H W 4 .M 5%

Patented July 31, 1951 METHOD OF TRANSFERRING FLUIDS Edgar L. Hinkson, Detroit, Mich., assignor to The General Detroit Corporation, Detroit, Mich., a

corporation of Michigan Application June 26, 1946, Serial No. 679,389

Claims. 1 The present invention relates to the art of transferring fluids under pressure from one container to another, particularly in connection with the handling of fluids which are stored in the compressed, liquid state, but which vaporize at ordinary temperatures and pressures. While the invention is particularly applicable to charging fire extinguishers with liquid carbon dioxide, such use will be recognized as representative rather than exclusive.

An important obj ect of the invention is to provide means whereby a greater quantity of a compressed fluid may be induced to flow into a receptacle to be charged than it has heretofore been possible to introduce without the use of a charging pump. In charging fire extinguisher flasks from a source of liquid carbon dioxide under high pressure, it has heretofore been common to apply a transfer pump, since when the source is directly connected to the flask, the pressure developed in the latter as the liquid level rises therein prevents adequate filling. For example, in filling such a flask which is designed to accommodate 15 pounds of carbon dioxide, if the flask is connected to a supply source having a pressure of approximately 900 pounds per square inch at a temperature in the neighborhood of 70 F., only about 11 pounds of CO2 will enter the flask before the transfer ceases due to equalization of pressures at the prevailing temperatures. When the meth- 0d of the present invention is practiced, however, it is possible, under the same conditions, without the use of a pump or other supplemental pressure generating apparatus, and in a quick, simple and convenient manner, to place a full charge of 15 pounds in such a flask from a source at the indicated pressure. Equivalent results are attainable with other proportions and pressures.

Other objects and advantages will be apparent upon consideration of the present disclosure in its or other fluid under pressure is connected to the flask In by means including a tube or hose l2 of suflicient length and flexibility to permit inverting the flask without disconnecting the tube. The flask is shown as a fire extinguisher body of the type and size designed to accommodate 15 pounds of CO2. Flasks of the indicated variety have a volumetric capacity in the neighborhood of 612-622 cubic inches, and are equipped with a valve l4 having a coupling nipple [6 through which the fluid is discharged during operation of the fire extinguisher, and to which the filler hose I2 is adapted to be connected in the manner indiv cated. Valve I4 is left open during all of the steps of the charging operation herein described and until the flask is full and ready for final sealing.

For convenience, the flask to be charged is preferably secured, as by means of the grappling chain [8, to the rotatable top cross bar 20 of an A-frame support 2-2, this arrangement being such that the flask may readily be inverted, to be supported either in the upright position in which it is shown in Figs. 1 and 2 of the drawings, or in the inverted position shown in Fig. 3, being stable in either position. The hose I2 is coupled at l3 to the supply pipe 25, a shut-off valve 24 being incorporated in the supply pipe, which is also provided with a manually operable vent valve 26 interposed between the shut-off valve and the coupling l3.

In carrying out the method of the invention, a small quantity (3 pounds is adequate in the case of a 15 pound flask) of liquid CO2 is admitted to the flask and the supply is then shut off at the valve 24. The flask is then inverted, to the position shown in Fig. 3, and vent valve 26 is opened, permitting the cooling charge to escape in gaseous form to the atmosphere. The flask is internally provided with a discharge siphon tube 28 extending from the valve M to a point near the bottom of the flask, so that with the flask in the inverted position shown in Fig. 3 the expanding refrigerating charge must escape through the then uppermost bottom portion of the flask and the arrangement is such that the gases sweep across and vaporize in intimate contact therewith although evaporation occurs within substantially all portions of the flask, which is rapidly cooled to a low temperature by such vaporization. When CO2 is utilized in the indicated manner, all of the three pound refrigerating charge escapes in gaseous form with the exception of approximately six ounces, which is solidifled. It is not necessary to await the vaporizationof -suc'h solidified portion, and valve 26 is closed when all but this has escaped. The flask is then returned to the upright position and valve 24 reopened. The temperature of the flask has been so reduced, in the manner above indicated, that the entering charge is chilled by the flask, and the pressure within the flask is resultantly maintained at such a relatively low level that a full chargeof poundsaof CO2 at room tempera: ture willreadily enter the flask-from a source-at a pressure of 900 pounds per square inch.

If too long an interval is allowed to elapse between the refrigeration of the flaskand the opening of valve 24 to admit the charge, so that the flask has partially warmed up, a pressure balance a may occur too soon, so that the inflow ceasessomewhat short of a full charge, due to the tendency of the entering charge towarm the .upper portions of the upright flask. If this occurs under conditions such that onlya relatively small percentage of the charge refuses to enter the flask, as forexample afterzl3 or lpounds have em tered a 15 pound flask, the requiredadditional'. charge may be induced to enter by again promptly inverting the flask tothe position shown inFig. 3; with-thevalve 24 vstill open. This carries-the chilled liquid into' contact withthe head portions of the flask andpromotes-uniform cooling of the flask, counteracting the warming of the headportion which has. resulted from the previous-inflow with the flask. in, the upright. position. If the interval.previously referredto was not too. great, such. uniform :cooling further or again. re-. duces theiinternal pressure, and an additional. quantity .of. fluidis thereby induced to enterthe flask, being: introduced thereinto'. through the siphontuberzt and above .the liquid level. A full chargexmay in this .manner beintroduced with theflaskat asomewhat. higher average temperature. The :flask -.ofcourse thenbesealed at the valve :1 4 inithe usual manner.

It will. be apparent that variations maybe introduced..without .departingfrom the spiritzqand scope of thesubjoined claims.

l. The-processv of. charging; with afluid .of the class;which isadaptedto bestored in the-1iquid.= staterunder pressurebut which vaporizes at ordirn-ary-,temperatures :and pressures; a receptacle of. the variety-having ahead having an ,:opening formed therein adapted to serve as arninlet through which, the receptacle maybe charged and a siphon tube-connected tosaid opening and extending to aremotepart of thereceptacle, :com. prisingconnecting the receptacle. to a high pres sure-source for ,alimited .periodof .time. to introe. duce into the receptaclea. relatively small quantity of, such fluid with thereceptacle in one.posi-. tion, interrupting the. connection between, the .receptacle and such. source, inverting. the. re: ceptacle, venting the fluid fromthereceptacle with the receptacle inthe inverted positionto reg irigeratethe receptacle by expansion ofthe es caping fluid, andre-establishing connection. be-

tween vthe receptacle and said high pressure source to permit the fluid to flow from the source. into the chilled receptacle.

2. The process of charging, with a fluidof the class which is adapted to be stored in. the liquid. state under pressure but which vaporizes at ordi.-' nary temperatures and pressures, a receptacle of thevariety having a head. having an opening formed. therein adapted to. serve .as. an inlet. through whichthe receptacle may be..charged.. andasiphontube.connected tosaid opening and eatending .;to.a-.1'emote part. of. the receptacla-coma,

prising connecting the receptacle to a high pressure source for a limited period of time to introduce into the receptacle a relatively small quantity of such fluid with the receptacle in a position in which the head is elevated and the siphon tube extends downwardly therefrom, interrupting the connection between the receptacle and such source, venting the fluid from the receptacle with the receptaclein a'position in which the head is lowered and the siphon tube extends upwardly therefrom to refrigerate the receptacle by expansion of the escaping fluid, and re-estab lishing connection between the receptacle and said high pressure source to permit the fluid to flowfrom the source into the chilled receptacle. 3. The process of charging, with a fluid of the class which is adapted to be stored in the liquid state under pressure but which vaporizes at ordinary temperatures and pressures, a receptacle of the variety having a head having an opening formed therein adapted to serve; as an inlet through which the receptacle may be. charged: and a siphon tube connected to-said opening and. extending to a remote part of the receptacle,-com.-.- prising connecting the receptacle to a high pres-: 1 sure source for a limited period of time to in: troduce into the receptacle a relatively small.., quantity of such fluid, interrupting the connec-, tion between the receptacle and such source venting the fluid from the receptacle with there-i. ceptacle in a positionin which the head is lowered and the siphon tube extends upwardly therefrom'to refrigerate the receptacle by expansion; of the escaping fluid, and re-establishing,oonneca. tion; between the receptacle .and said vhighpres-s sure source .to permit the fluid to flow fromqthee source into the chilled receptacle with the chilled; receptacledisposed with the *head elevated, al-.- lowingsuch inflow to continue afterreconnection ,1 of; the receptacle to the sourcexuntil-a substan tial balance is reached at the prevailing -conditions of-temperatureand pressure, the fluid from the sourcebeing at a highertemperature than 1 the chilled receptacle, whereby'the. fluid tends to warm the receptacle nonuniformlyduring. inflow thereinto due to the fact that heat. .isflrst fabrsorbed from :the fluid in the vicinity of the open-. mg and. head, and thereafter againturning, the receptacleto a position in which the head is deepressed to permit more extended contact, between, the fluid and the receptacle-and therebypromote more uniform heat absorptionfrom thefluidhby a. greater proportion of the massof the receptacle; whereby the pressure prevailing within the recep; tacle is reduced to permit additional fluid inflow.

4. The process of charging with an expansiblef fluid .from high pressure source-a receptacle of; the variety having an opening,adaptedto'serVe: as an inletthrough which it mayybe.-charged,

which'comprises precooling the receptacle. con? necting the receptacle to the source so that ,thefluid may flow from the source into the receptacle through said opening while thelatter/is disposed in a position in which the inlet opening is-near.- the: top, the fluid flowin through said opening; until asubstantial balance is reached at theiprevvailing conditions of temperatureand -.-pressure,' the fluid from the source being at ia'highentem-r perature than the precooled -recep tacle, whereby uthe fluid tends to warm the receptaclez-duringitsi inflow thereinto and wherebysuch heatingrof-the receptacle occurs non-uniformly, due -totheg facta that heat is first absorbed from the-.fluid-.-in the vicinity, of the inlet, while. the fluid. -thus.;cooled-f :flowstoand remains longer in. contact withiotherz parts of the receptacle remote from the inlet, inverting the position of the receptacle to induce flow of the fluid into contact with a greater area of the interior of the receptacle, whereby heat absorption from the fluid occurs over a large portion of the internal surface area of the receptacle and the pressure prevailing within the receptacle is thereby reduced, and thereafter, and before the receptacle again warm up beyond a desired temperature permitting the fluid to flow from the source into the portion of the receptacle within which the pressure has been so reduced.

5. The process of charging, with a fluid of the class which is adapted to be stored in the liquid state under pressure but which vaporizes at ordinary temperatures and pressures, a receptacle of the variety having a head having an opening formed therein adapted to serve as an inlet through which the receptacle may be charged and a siphon tube connected to said opening and extending to a remote part of the receptacle, comprising connecting the receptacle to a high pressure source for a limited period of time to introduce into the receptacle a relatively small quantity of such fluid with the receptacle in a position in which the head is elevated and thesiphon tube extends downwardly therefrom, interrupting the connection between the receptacle and such source, venting the fluid from the receptacle with the receptacle in a position in which the head is lowered and the siphon tube extends upwardly therefrom to refrigerate the receptacle by expansion of the escaping fluid, and re-establishing connection between the receptacle and said high pressure source to permit the fluid to flow from the source into the chilled receptacle with the 6 chilled receptacle disposed with the head elevated, allowing such inflow to continue after reconnection of the receptacle to the source until a substantial balance is reached at the prevailing conditions of temperature and pressure, thefluidfrom the source being at a higher temperature than the chilled receptacle, whereby the fluid tend to warm the receptacle non-uniformly during inflow thereinto due to the fact that heat is first absorbed from the fluid in the vicinity of the opening and head, and thereafter again turning the receptacle to a position in which the head is depressed to permit more extended contact between the fluid and the receptacle and thereby promote more uniform heat absorption from the fluid by a greater proportion of the mass of the receptacle, whereby the pressure prevailing within the receptacle is reduced to permit additional fluid EDGAR L. I-IINKSON.

REFERENCES CITED The following references are of record in the file of this patent: 

